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So,

I have disassemble completely the differential and I have order the 4 bearings that I will change.

Is there any advice regarding the re assembly of the differential ?

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Hi Serge and All,


I advise not to change the bearings in the 2000/2600 differentials, because almost all were very good and heave no wear.

Only if someone forgot to put oil in it but then are also all gears worn !!

If putting the diff. together with NEW bearing you NEED the special Alfa 2600 tools because all the bearing and play on the gearwheels have a pretension and must be adjust in 0,001 tolerances otherwise there is a great chance that the diff. is going to make noise........

rgds Franco
 

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So,

I have disassemble completely the differential and I have order the 4 bearings that I will change.

Is there any advice regarding the re assembly of the differential ?
The procedure is described in the 2000 Suspension Shop manual (about 7 pages total, included in the CarDisc DVD). The special tools Franco mentions are described in tool bulletins.

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Time for a specialist?

I agree with Franco now its apart you will have to take the differntial to an axle specialist to set up. I had a Ford axle set up this way with no problems, the principle is the same on all and I am sure general setup equipment can be used for this as I doubt if the original alfa tools exist now. The next challenge may be finding shims for the set up , however , the differntial may be common across different alfa romeo models ( hopefully)
 

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Serge,

There is a company in the UK which makes circular shims to custom sizes but in Imperial thicknesses only, it seems (LINK). They also make other shims in custom shapes. Perhaps you can find a similar company somewhere in France .....

Alex.

PS: I have a wide but incomplete selection of 101, 105 and 105.64 gearbox and rear axle shims. If you really get stuck, send me an email and I'll try to see if something can work.
 

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Well, I did this a few months ago. My original pinion gear is damaged and, although useable, it is very noisy. I bought another differential, which had some rust on the gears and rebuilt it with all new bearings. I had the gear teeth coated with a ceramic coating that is baked on and mostly ends up in the pores of the metal. It can not fill the rust pits, but just makes the surfaces more slick. I have the factory tool for setting the pinion depth, but improvised the other tools. I made a tool, similar to the one shown in Ruedi's post above, to check the pinion bearing pre-load, but used a different method using the weight of a bucket of water and a string around a cylinder. I compared both readings and they were very close. Since the weight of the bucket can be varied infinitely by adding water, I liked this method better. I have a hydraulic press that was used to repeatedly remove and install the pinion bearings with different shims to get the pinion depth correct and then get the bearing pre-load correct. To set the side bearing pre-load, you will need to make a very robust tool to fit the four holes in the large ring-nuts. I used an 18" long breaker bar on this tool and you may need to use as much as 100 foot-pounds of torque to get it right! This is a tedious adjustment which also is used to set the ring gear backlash. I purchased the pinion shims from an industrial supply house in Atlanta, Georgia USA (McMaster-Carr). I will try to post some pictures.
Larry Bono
 

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I should add that I have not yet installed this differential and, therefor, I do not know if my work was successful.
Larry
 

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With my 1" - 2" micrometer, which I believe to be accurate, I measure 1.417" (35.99 mm). This seems odd, and it is quite possible that it should be 36 mm. I got this tool about a year ago and it shows some damage from surface rust, so it may have lost .0005" (.01 mm) diameter from polishing.
Larry Bono
 

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I had the gear teeth coated with a ceramic coating that is baked on and mostly ends up in the pores of the metal. It can not fill the rust pits, but just makes the surfaces more slick.
Larry, can you tell us a bit more about this process (which I find very intriguing)? How did you learn of it? What are the pros and cons? Who did the job and was it expensive?

I didn't Google this topic but if you have any links to read up upon this topic, I'd greatly appreciate it.
 

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Ruedi, when I showed the rusted gears (see picture below) to a mechanic friend of mine, he suggested that I have them coated. It is a dry-film lubricant that is baked at 350 degrees F. and then burnished. The result is a very thin film, maybe only .0001" and so there is no appreciable dimensional change. I cannot say if it will have any effect or not. For all I know, it may be just more "snake oil" hype, but I thought it would not hurt anything. I think it was about $75. I am hoping for quieter running than the original unit in the car, which is VERY noisy and ruins the driving experience. The company is Tech Line Coatings and the product is CermaLube dry-film lubricant. I hope the link below works. I still have not figured out how to patch a link.
Tech Line Coatings | Automotive ( Hi-Performance ) Coatings

Larry Bono
 

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I hate to say it, but I'm betting your work will not result in quieter running.

Not long ago I saw an ad for a NOS ring and pinion set for the 102. I think it was on eBay | Tecnologia, moda, fai da te: prodotti nuovi a prezzo fisso, but not sure. They are rare, but out there. I'd go that way.

My rear end is noisy when I have the convertible top erected. Silent with it down. Solution is easy. Top-down driving only.
 

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Don, I am fully prepared for disappointment with my newly-acquired differential. Last year, after getting the factory tool for setting the pinion depth, I disassembled my original unit thinking I could make some adjustments to reduce the horrible noise. It turned out that the pinion depth was right on specification, but the ring-gear backlash was excessive, which had resulted in the pinion gear teeth having pronounced ridges near the root. My work resulted in no change. When I told my 50 year old son, an accomplished amateur cellist, that a month's work resulted in "no change, just as noisy as before", he said that is the same result he gets after a month of practicing the cello, "no change, just as noisy as before".
Larry
 

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Thanks for the background on ceramic coating, Larry -- may your diff be quieter than a Cello!
 

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Hi All,

you can reduce the noisy by using better quality diff. oils

a friend of me used LUCAS synthetic oil in a lot of english cars which have the same diff. as used on AR 1900/2000/2600

I am told that alfa also bought the diff. by a british company.

In my 105 seri cars I use LS diff. oil and that gives also lower nois

rgds Franco
 

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Franco, can you tell us which English differentials are the same as ours?
Thanks,
Larry Bono
 
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